Closed head socket-head screw or bolt



Oct. 1s, 1938.

w D. WEBB 2,133,409

CLOSED HEAD SOCKET HEAD SCREW OR BOLT Filed Sept. 14, 1957 24 1o'- Ii I6 |3 l4 l5 FIG. 2 FIG. 4

'7: V I |3- l4 J' 5 26 27 I7 FIG. 7

Jnnenfor fii WESLEY 0. WEBB y I I W a" (Ittorneg Patented Oct. 18, 1938 UNITED STATES PATENT OFFICE CLOSED HEAD SOCKET-HEAD SCREW OR Application September 14, 1937, Serial No. 163,819

1 Claim.

This invention relates primarily to screws, bolts and the like which are formed with round heads or bodies provided with an axial socket either hexagonal, square, triangular or of any other poly-sided shape in cross-section and by which it may be rotated by a special'wrench to tighten or loosen it in a tapped hole.

The invention relates more particularly to means incorporated therein for closing the outer end of the socket opening to prevent its becoming filled with dirt or other foreign matter which would require cleaning out the socket before the end of the wrench could be inserted.

The object of the invention is to provide a round-head socket screw or bolt having a normally closed socket.

Another object of the invention is to provide a machine screw, bolt or the like having an axial socket in the head which is provided with a cover or closure to protect and close the socket from collecting dirt, grit or other foreign matter.

Another object of the invention is to provide an article of this kind in which the socket is normally closed, but which may be readily opened to receive a tool or wrench by which it may be rotated.

A further object of the invention is to provide a closing means for a socket which may be depressed into the socket by the insertion of a tool or wrench preparatory to rotating the article.

With these and other objects in view, my invention consists in certain novel construction and combination of parts as will hereinafter be fully described and claimed and further illustrated in the accompanying drawing which forms a part hereof and in which like figures of references refer to corresponding parts in all of the views, but it is understood that slight changes may be made without departing from the spirit of the invention.

In the drawing:

Figure 1 shows the end of the head of a sockethead cap-screw with my invention embodied therein.

45 Figure 2 is a side view of a socket-head capscrew showing the head in section to illustrate the construction and combination of parts.

Figure 3 is a vertical sectional view of a sockethead cup point set-screw showing my invention as applied thereto.

Figure 4 shows a vertical sectional view of a socket-head cap-screw with my invention incorporated therein and showing the position assumed by the closure cap when the end of a wrench is inserted into the socket upon the closure cap.

Figure 5 shows a top plan view of the closure cap.

Figure 6 shows a sectional View of the same.

Figure 7 shows a vertical sectional view of a socket-head pipe lug in which my invention is incorporated.

Referring to the drawing:

In Figures 1, 2 and 4, I have shown the usual type of socket-head cap-screw, comprising a round head it, formed on the shank H and provided with the external threads Hi.

The head it is formed with the axial hexagonal socket [3 for the reception of a bar-wrench or other tool by which the screw may be rotated.

Communicating with the lower or closed end of this socket i3 is formed an axial recess M of smaller diameter than that of the socket, and again communicating with this recess is a threaded hole l5, within which is threaded the lower end of a pin 16 which is provided with a head I8 the end of which is flush with the end of the head l0.

Slidably mounted on this pin l6 and forming a slide lit with the wall of the socket I3 is a closure cap or plug I! of the same shape as that of the socket and which may be either square, triangular, hexagonal or any poly-sided shape in cross-section and this closure cap I! is formed with an axial countersunk hole 25 to fit the head E8 of the pin I6.

For normally retaining the closure cap I! in flush relation with the end of the head It, a spiral spring I 9 is mounted on the pin it with its lower end in the recess l4 and its upper end pressing against the under surface of the closure cap ll.

It will thus be seen that normally the closure cap ll is held by the spring i9 with its upper face flush with both the head of the screw [6 and the head I0 of the cap-screw ll.

Referring to Figure 4, it is the usual practice to employ with socket-head screws, bolts and the like, a wrench in the form of a bent bar of the same shape in cross section as the socket opening in the screw or bolt, and I have here shown such a bar-wrench 23, but have formed the same with an axial bore or recess 24 in the end thereof.

In applying the bar-wrench 23 to the screw head It], the end of the wrench is pressed downward upon the closure cap I! forcing it downward Within the socket I3 against the pressure of the spring [9, the recess 24 in the end of the wrench 23 allowing the pin IE to enter as shown in Figure 4, and in this manner the end of the wrench 23 As shown in Figure 7 of the drawing, the in vention is applied to a pipe lug 26 having the external threads 2'0, and it is thus seen that the invention may be applied to any socket in many different articles.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent, is:

A bolt having a socket in its head, a pin fixed axially in the socket and having a head thereon,

the upper surface of which is in a plane with the upper surface of the bolt head, a closure plate slidable on the pin and having its periphery intimately engaged with the wall of the socket, and a spring in the socket and engaged with the plate 10 to hold the same yieldably engaged with the head of the pin and the upper surface of the plate in a plane with the upper surface of the bolt head. WESLEY D. WE'BB. 

